@misc{RothTippkoetter2016, author = {Roth, J. and Tippk{\"o}tter, Nils}, title = {New Approach for Enzymatic Hydrolysis of Lignocellulose with Selective Diffusion Separation of the Monosaccharide Products}, series = {Chemie Ingenieur Technik}, volume = {88}, journal = {Chemie Ingenieur Technik}, number = {9}, publisher = {Wiley-VCH}, address = {Weinheim}, issn = {0009-286X}, doi = {10.1002/cite.201650301}, pages = {1237}, year = {2016}, abstract = {Enzymatic hydrolysis of lignocellulosic material plays an important role in the classical biorefinery approach. Apart from the pretreatment of the raw material, hydrolysis is the basis for the conversion of the cellulose and hemicellulose fraction into fermentable sugars. After hydrolysis, usually a solid-liquid separation takes place, in order to separate the residual plant material from the sugar-rich fraction, which can be subsequently used in a fermentation step. In order to factor out the separation step, the usage of in alginate immobilized crude cellulose fiber beads (CFBs) were evaluated. Pretreated cellulose fibers are incorporated in an alginate matrix together with the relevant enzymes. In doing so, sugars diffuse trough the alginate matrix, allowing a simplified delivery into the surrounding fluid. This again reduces product inhibition of the glucose on the enzyme catalysts. By means of standardized bead production the hydrolysis in lab scale was possible. First results show that liberation of glucose and xylose is possible, allowing a maximum total sugar yield of 75 \%.}, language = {en} } @article{SelmerPierikHeider2005, author = {Selmer, Thorsten and Pierik, Antonio J. and Heider, Johann}, title = {New glycyl radical enzymes catalysing key metabolic steps in anaerobic bacteria}, series = {Biological Chemistry. 386 (2005), H. 10}, journal = {Biological Chemistry. 386 (2005), H. 10}, isbn = {1431-6730}, pages = {981 -- 988}, year = {2005}, language = {en} } @article{OehlenschlaegerVolkmarStiefelmaieretal.2024, author = {Oehlenschl{\"a}ger, Katharina and Volkmar, Marianne and Stiefelmaier, Judith and Langsdorf, Alexander and Holtmann, Dirk and Tippk{\"o}tter, Nils and Ulber, Roland}, title = {New insights into the influence of pre-culture on robust solvent production of C. acetobutylicum}, series = {Applied Microbiology and Biotechnology}, volume = {108}, journal = {Applied Microbiology and Biotechnology}, publisher = {Springer}, address = {Berlin, Heidelberg}, issn = {1432-0614}, doi = {10.1007/s00253-023-12981-8}, pages = {10 Seiten}, year = {2024}, abstract = {Clostridia are known for their solvent production, especially the production of butanol. Concerning the projected depletion of fossil fuels, this is of great interest. The cultivation of clostridia is known to be challenging, and it is difficult to achieve reproducible results and robust processes. However, existing publications usually concentrate on the cultivation conditions of the main culture. In this paper, the influence of cryo-conservation and pre-culture on growth and solvent production in the resulting main cultivation are examined. A protocol was developed that leads to reproducible cultivations of Clostridium acetobutylicum. Detailed investigation of the cell conservation in cryo-cultures ensured reliable cell growth in the pre-culture. Moreover, a reason for the acid crash in the main culture was found, based on the cultivation conditions of the pre-culture. The critical parameter to avoid the acid crash and accomplish the shift to the solventogenesis of clostridia is the metabolic phase in which the cells of the pre-culture were at the time of inoculation of the main culture; this depends on the cultivation time of the pre-culture. Using cells from the exponential growth phase to inoculate the main culture leads to an acid crash. To achieve the solventogenic phase with butanol production, the inoculum should consist of older cells which are in the stationary growth phase. Considering these parameters, which affect the entire cultivation process, reproducible results and reliable solvent production are ensured.}, language = {en} } @article{SchererKratzGoberetal.1992, author = {Scherer, Ulrich W. and Kratz, J. V. and Gober, M. K. and Zimmermann, H. P.}, title = {New nuclide 263 105 / J.V. Kratz, M.K. Gober, H.P. Zimmermann, M. Sch{\"a}del, W. Br{\"u}chle, E. Schimpf, K.E. Gregorich, A. T{\"u}rler, N.J. Hannink, K.R. Czerwinski, B. Kadkhodayan, D.M. Lee, M.J. Nurmia, D.C. Hoffman, H. G{\"a}ggeler, D. Jost, U.W. Scherer, A. Weber}, series = {Physical Review C . 45 (1992)}, journal = {Physical Review C . 45 (1992)}, pages = {1064 -- 1069}, year = {1992}, language = {en} } @article{ThielTippkoetterSucketal.2013, author = {Thiel, Alexander and Tippk{\"o}tter, Nils and Suck, Kirstin and Sohling, Ulrich and Ruf, Friedrich and Ulber, Roland}, title = {New zeolite adsorbents for downstream processing of polyphenols from renewable resources}, series = {Engineering in Life Sciences}, volume = {13}, journal = {Engineering in Life Sciences}, number = {3}, publisher = {Wiley}, address = {Weinheim}, doi = {10.1002/elsc.201200188}, pages = {239 -- 246}, year = {2013}, abstract = {Commercial materials with polyvinylpolypyrrolidone and polymeric amberlites (XAD7HP, XAD16) are commonly used for the adsorptive downstream processing of polyphenols from renewable resources. In this study, beta-zeolite-based adsorbent systems were examined, and their properties were compared to organic resins. Batch adsorption experiments were conducted with synthetic solutions of major polyphenols. Adsorption isotherms and desorption characteristics of individual adsorbent were determined based on these results. Maximum adsorption capacities were calculated using the Langmuir model. For example, the zeolites had capacities up to 203.2 mg/g for ferulic acid. To extend these results to a complex system, additional experiments were performed on rapeseed meal and wheat seed extracts as representative renewable resources. HPLC analysis showed that with 7.5\% w/v, which is regarded as the optimum amount of zeolites, zeolites A and B could bind 100\% of the major polyphenols as well as release polyphenols at high yields. Additionally, regeneration experiments were performed with isopropyl alcohol at 99°C to evaluate how zeolites regenerate under mild conditions. The results showed only a negligible loss of adsorption capacity and no loss of desorption capacity. In summary, it was concluded that beta-zeolites were promising adsorbents for developing new processes to isolate polyphenols from renewable resources.}, language = {en} } @article{ElbersGaebHoffmannetal.2006, author = {Elbers, Gereon and G{\"a}b, Martina and Hoffmann, Katharina and Lobe, Melanie}, title = {NIR-spectroscopic investigation of foliage of ozone-stressed Fagus sylvatica trees / G{\"a}b, Martina ; Hoffmann, Katharina ; Lobe, Melanie ; Metzger, Rut ; Ooyen, Sven van ; Elbers, Gereon ; K{\"o}llner, Barbara}, series = {Journal of Forest Research. 11 (2006), H. 2}, journal = {Journal of Forest Research. 11 (2006), H. 2}, isbn = {1341-6979}, pages = {69 -- 75}, year = {2006}, language = {en} } @article{TippkoetterRoikaewUlber2008, author = {Tippk{\"o}tter, Nils and Roikaew, W. and Ulber, Roland}, title = {Nitrate removal from whey concentrate with biotechnological regeneration of the waste water}, series = {European dairy magazine : EDM}, journal = {European dairy magazine : EDM}, number = {1}, isbn = {0936-6318}, pages = {30 -- 32}, year = {2008}, language = {en} } @article{BrabandPaulssenAbram2006, author = {Braband, Henrik and Paulßen, Elisabeth and Abram, Ulrich}, title = {Nitridorhenium(V) Complexes with 1,3-Dialkyl-4,5-dimethylimidazole-2-ylidenes}, series = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry}, volume = {632}, journal = {Zeitschrift f{\"u}r anorganische und allgemeine Chemie : ZAAC = Journal of inorganic and general chemistry}, number = {6}, issn = {1521-3749}, doi = {10.1002/zaac.200600002}, pages = {1051 -- 1056}, year = {2006}, language = {en} } @article{BaumannSemenehDehairsetal.1998, author = {Baumann, Marcus and Semeneh, M. and Dehairs, F. and Elskens, M.}, title = {Nitrogen uptake regime and phytoplankton community structure in the Southern Ocean / Semeneh, M. ; Dehairs, F. ; Elskens, M. ; Baumann, M.E.M. ; Kopczynska, E.E. ; Lancelot, C. ; Goeyens, L.}, series = {Journal of Marine Systems. 17 (1998), H. 1-4}, journal = {Journal of Marine Systems. 17 (1998), H. 1-4}, isbn = {0924-7963}, pages = {159 -- 177}, year = {1998}, language = {en} } @article{KotterGregerIhme1984, author = {Kotter, Michael and Greger, M. and Ihme, B.}, title = {Nonequilibrium phase transitions with hysteresis in solid catalysts : the system copper-oxygen-propene / M. Greger ; B. Ihme ; M. Kotter ...}, series = {Berichte der Bunsen-Gesellschaft f{\"u}r Physikalische Chemie. 88 (1984)}, journal = {Berichte der Bunsen-Gesellschaft f{\"u}r Physikalische Chemie. 88 (1984)}, isbn = {0005-9021}, pages = {427 -- 433}, year = {1984}, language = {en} }